The importance of raw material quality

The quality of the raw materials for Lactoferrin production is defined using different aspects: Besides the purity (the Lactoferrin protein amount relative to the total protein amount), quality is also defined via the degree to which it has been denatured, the bio-activity, and the removal of any potentially harmful, adherent substances.  In this context, purity also refers to other components of milk such as casein or lactose.
The quality criteria are dependent on the quality of the whey, and on the extraction process, which influence the integrity & functionality of the Lactoferrin. 
Also crucial, are the iron-binding capacity, and iron saturation properties, that remain after the extraction.  The original functions of Lactoferrin include the binding, transport & delivery of iron – meaning that the iron-binding characteristics are valid measurement parameters.  The saturation of the iron-binding sites of naive Lactoferrin should be between 20-30%.
Additional info: There are 2 forms of Lactoferrin, Apo- and Holo-Lactoferrin.  With Apo-Lactoferrin, less than 5% of the iron-binding locations are occupied, meaning it is ready to transport iron as needed, and can therefore help regulate iron metabolism.  Holo-Lactoferrin, in comparison, is more than 80% saturated.
Poor purification, or a high grade of protein denaturation, can leave impurities such as lactoperoxidase, lipopolysaccharides, or angiogenin present.  These can significantly affect the functionality of the Lactoferrin.
Note: lactose content is also used as a measure of the purity.  Specifications for lactose content of the raw material should be at least in the permillage range (parts per thousand) per 100mg Lactoferrin, so that people with lactose intolerance can still utilise the final product.  
In order to guarantee a consistent quality of the raw materials, standardised processes and validated test methods are used.  Thus, the structural and functional characteristics can be proven and verified. Accordingly, purified Lactoferrin is preferred for commercial product development.